* {
    margin: 0;
    padding: 0;
    outline: none;
    box-sizing: border-box;
}
body {
    overflow: scroll;   /*否则当网页出现下拉框时会导致界面微微移动*/
    background-color: #f3f5f7;
    font: 14px/1.5 "Microsoft YaHei UI", sans-serif;
    color: #333;
}
a {
    text-decoration: none;
    color: #333;
}
li {
    list-style: none;
}